refactor: update TransactionContext to use concrete type for __aenter__ method

Author: vlakius

tortoise/backends/base/client.py

@@ -306,14 +306,14 @@ async def __aexit__(self, exc_type: Any, exc_val: Any, exc_tb: Any) -> None:
         self._lock.release()
 
 
-class TransactionContext(Generic[T_conn]):
+class TransactionContext:
     """A context manager interface for transactions. It is returned from in_transaction
     and _in_transaction."""
 
     client: TransactionalDBClient
 
     @abc.abstractmethod
-    async def __aenter__(self) -> T_conn: ...
+    async def __aenter__(self) -> TransactionalDBClient: ...
 
     @abc.abstractmethod
     async def __aexit__(self, exc_type: Any, exc_val: Any, exc_tb: Any) -> None: ...

tortoise/backends/sqlite/client.py

@@ -16,7 +16,6 @@
     Capabilities,
     ConnectionWrapper,
     NestedTransactionContext,
-    T_conn,
     TransactionalDBClient,
     TransactionContext,
 )
@@ -191,7 +190,7 @@ async def ensure_connection(self) -> None:
             await self.connection._parent.create_connection(with_db=True)
             self.connection._connection = self.connection._parent._connection
 
-    async def __aenter__(self) -> T_conn:
+    async def __aenter__(self) -> TransactionalDBClient:
         await self._trxlock.acquire()
         await self.ensure_connection()
         self.token = get_connections().set(self.connection_name, self.connection)